Molded case industrial-rated circuit breakers such as described within U.S. Pat. No. 4,982,173 employ a pair of separable contacts and an operating mechanism wherein the contacts are restrained from being driven to their open position against the bias of a pair of powerful operating mechanism springs under quiescent circuit current conditions. The circuit breaker operating mechanism rapidly drives the contacts to their open positions upon the occurrence of an overcurrent condition. An external operating handle is employed to turn the contacts between open and closed conditions usually to energize associated electrical equipment.
When such a circuit breaker is located at a location remote from the associated equipment, a motor operator device engages the operating handle and moves the handle under driving force provided by a remotely-switched electric motor. U.S. Pat. No. 3,171,920 describes one such motor operator used to control a remote circuit breaker. However, to prevent faulty operation of the motor operator during the installation process, a skilled operator is usually employed to insure that the circuit breaker contacts are open and the circuit breaker operating handle is in the OFF position when the motor operator is in the OFF position and the circuit breaker operating handle is in the ON position when the motor operator is in the ON position to prevent inadvertent damage to the circuit breaker operating handle.
It would be economically feasible to align the motor operator ON and OFF positions with the circuit breaker ON and OFF positions automatically and without requiring any such skilled operator.
Accordingly, the invention proposes an improved motor operator device which can automatically align the motor operator and associated circuit breaker mechanical logic states without human intervention.